Not really, its based on threat level. As a level 67 Dark Templar, I can keep agro on multiple mobs, you just need to be doing damage with high taunt and high hate gear.

Not the agro I ment, I ment the ability to pull mobs. I can dance infront of a mob and for some reason a mob 5 miles away attacks me insted of the one 5 feet away. It's also not possible to single pull from what I have seen and if you did manage to pull a single out of a group it was a fluke thanks to the retarded agro system.

Hide is also broken with the whole visibility in light crap. I have been able to sneak better in sunlight then in some dungeons or even at night... and I have max points in hide for my lvl.